A proxy server can be used as an access point to the Internet. As another application, a proxy server can also be used as an access point for a virtual private network (VPN).
A proxy server can typically be used as an access point to the Internet as follows. A client browser can be configured such that all of the client's HTTP requests are directed to the proxy server for the Internet before the HTTP request is forwarded to the Internet. The proxy configuration for the client browser may be manually configured by a user, or may be autoconfigured by employing, for example, a script. Upon receiving the HTTP request, the proxy server for the Internet determines whether it has a copy of the requested object stored locally. If so, the proxy server for the Internet responds to the HTTP request. If not, the proxy server for the Internet employs a TCP connection over the Internet to a destination server. The proxy server then employs the TCP connection to send the HTTP request to the destination server associated with the HTTP request. If the request is successful, the destination server sends the requested object to the proxy server for the Internet, and the proxy server for the Internet sends the requested object to the client browser.
In addition to the caching functionality previously described, a proxy server may be configured to provide various security and administrative control services. For example, a proxy server may be configured to filter requests that are received by the proxy server. Also, a proxy server may be employed to mask the identity of the client browser that originated the request to the destination server.